Pfizer have heavily promoted Exubera in the two years it has been on the market, yet sales of the drug remain tiny. Overall, it accounts for less than 1 per cent of the total insulin market.

The withdrawal of Exubera is expected to cost some $2.8 billion. This renders the entire fiasco one of the most expensive flops in pharmaceutical history. Pfizer, who are the largest drug company in the world, have faced a rocky road recently.

The decision raises greater overall questions about the potential for inhaled insulin to command strong sales and compete with normal injectable insulin. The chairman of Pfizer reportedly concluded: "Despite our best efforts, Exubera has failed to gain the acceptance of patients and physicians."